In local area networking for telephone systems, connections between transmission media are made through connectors mounted on patch panels. Typically, a patch panel includes a plate having an array of openings therein, in which are mounted connectors or, for high density applications, connector modules. Such patch panel and connector arrangements are used with optical fiber connectors, coaxial cable connectors, and copper wire modular connectors.
In local area networking and telecommunication hookups, especially in customer premises, it is often necessary to connect particular telephone or other apparatus such as computer lines which extend from a particular piece of equipment at a particular physical location to other equipment circuits which extend from, for example, a PBX or LAN network to a central switching facility. In the past, this cross-connection has been within the province of a telephone company craftsperson upon a customer's request. However, because of the changing nature of the telephone industry, with responsibilities being shifted more and more to the individual customer, it has become the practice to have the customers make their own telephone and equipment arrangements and hook-ups without reliance on the use of skilled personnel.
Such reliance upon the customer to make such hook-ups or cross-connections gives rise to numerous problems leading to efforts on the part of distribution hardware equipment manufacturers to simplify the process as much as possible. One problem has been the use of insulation displacement connectors (IDC) on the connector module in, for example, local area network (LAN) connecting or distribution fields, wherein the wires are forced between the blades of the IDC for both mechanical and electrical connection. Such an operation often requires both special tools and special skills, and presents a definite area for simplification. Also, the installation must be such that there is ready access to the connectors for performing the wiring operation. A second problem arises because typical cross-connect units must be individually secured to mounting surfaces. All of the wires involved must be routed, dressed, and connected properly, and usually present to the assembler an unintelligible mass of intertwined and often tangled wires.
One proposed solution to at least some of the foregoing problems is shown in U.S. Pat. No. 4,536,052 of Baker et al. In the arrangement of that patent, a modular cross-connect panel is designed to allow multi-conductor cables carrying a number of line circuits to be plugged into mating connectors. The connectors from the lines as well as from the stations are pre-wired to standard telephone jacks thereby allowing the customer to snap one end of a double plug-ended cord into the desired line jack and the other end of the cord into the desired station jack. The cross-connect comprises a housing having several hinged rotating section connector panels, each of which accepts multi-pair cables. The hinged section is mounted to a forward edge of a support section and the multi-pair cables are suspended between the two sections. Included in each section are a plurality of jacks arranged in groups, vertically spaced from each other. The individual cable pairs within the cable are connected to individual jacks and the double plug-ended path cords are then used to cross-connect individual stations with switching facility lines. The jacks are grouped in sets of six mounted on plug boards which are mounted on the panel by means of ramps molded on each of the individual jacks. Thus, the jacks, which are mounted on the board, retain the board within openings to the panel. The cables leading to the jacks from, for example, a PBX are each fitted with an end connector which, in turn, is adapted to plug into the rear of each set of six jacks. Such an arrangement necessitates a pre-wiring and connector mounting of the cables, which is beyond the normal competence of the customers, and which reduces the flexibility of the arrangement. Any changes that may be desired to be made to the jack connections can necessitate a rewired connector on the cable, which is undesirable from both a time and cost standpoint.
The use of the jacks to retain the plug board on the panel can cause problems inasmuch as, for secure mounting, each plug board must have a full complement of jacks. In addition, such an arrangement necessitates the use of jacks having ramps molded thereon rather than standard jacks which have no ramp.
A universal patch panel is shown in U.S. Pat. No. 5,238,426 of Arnett and in U.S. Pat. No. 5,302,140 of Arnett, wherein a panel has an array of a plurality of openings therein. Each opening is adapted to receive a mounting adapter of plastic material having first and second depressible cantilever beams, which function to hold the adapter within the opening. The adapter, in turn, has grooves in the interior side walls thereof for holding a connector having resilient tabs therein. Each individual connector is wired and then inserted into and locked within the adapter. This arrangement allows any of a number of different types of connectors to be individually mounted in the panel, provided each connector has resilient tabs for locking the connector in place within the adapter. When the panel contains a full complement of connectors so mounted, cross-connections among different connectors can easily be made from the front of the panel by the customer.
In both the Arnett and Baker et al. arrangements, the wiring of the connectors and, more particularly, the modules, is preferably performed by a skilled craftsperson, in addition to which the modules must be assembled and mounted on the patch panel by the craftsperson. Mounting the modules or connectors may, as in the Arnett arrangement, entail the use of a mounting adapter or, as is common in the prior art, the use of mounting screws. Additionally, it is common in the prior art to mount the front portion of the module to the front of the patch panel and the rear portion to the rear of the panel. Also, where the module includes a printed circuit board it is common to mount the board on stand-offs extending from the module housing.
It is desirable, for economic reasons, that there be a reduction in complexity of apparatus and of assembly time. In addition, where the panels are contained in locations of limited space, such as closets, it is desirable that the modular mounting occupy as little additional space as possible. Inasmuch as the subscriber is expected to operate the mounted panel, i.e., plug and unplug wires and cables, a neat appearance without a confusion of wires and connection would, likewise, be desirable.